Propylene dimerization



United States Patent 3,219,723 PROPYLENE DIMERIZATION Lewis W. Hall, Jr., Claymont, Del., assignor to Sun Oil Company, Philadelphia, Pa., a corporation of New 3,219,723 Patented Nov. 23, 1965 'ice these halides are inoperative for the present purpose, as their reaction products with the sodium are ineffective as catalysts for dimerizing propylene.

Contact of the propylene with the catalyst system can Jersey 5 be carried out either in the presence or absence of an N0 Drawing Filed Man 14, 1963, No. 265,068 inert reaction medium such as pentane, heptane, octane, 4 (33mm (CL decane, benzene or any hydrocarbon solvent which is inert to the catalyst. The temperature of contact should be This application is a continuation-in-part of copending in the range of 100250 C. and preferably ISO-200 C. application Serial No. 127,127, filed July 27, 1961, and The operation can be conducted batchwise or in a flow now abandoned. reactor either with the hydrocarbons and catalyst both This invention relates to the preparation of methylflowing therethrough or with the hydrocarbons passing pentenes by the dimerization of propylene under certain through a bed of the catalyst. After separation of the catalytic reaction conditions. hydrocarbon reaction product from the catalyst, the

The catalytic polymerization of propylene ordinarily methylpentenes can be recovered in pure form by distilresults in a mixture of polymerization products which lation. vary considerably in molecular weight and which may The reaction product of the present process is comrange from liquid to solid polymers. Recently certain posed of a mixture of methylpentene isomers, the proportypes of catalysts have been developed which have the tions of which vary dependent upon the particular reacunique property of dimerizing propylene forming hexenes 2 tion conditions used. Short reaction times tend to favor as the major product. These dimerization products the formation of 4-methylpentene-1 while longer reaction which are primarily methylpentenes are highly desired as times tend to cause the formation of other methylpentene high octane components of motor fuels. Certain of the isomers such as 2-methylpentene-2 and 4-methylpentene-2. methylpentenes particularly 4-methylpentene-1 are useful The following examples illustrate the invention more as monomers in the production of polyolefin resins. specifically.

It has generally been disclosed in the prior art that Example I Kali i catalysts inffluding h 9 A catalyst was prepared by dispersing 3.0 grams of slum, rubidium and cesium are suitable for dimerizin sodium metal and 50.0 grams of sodium chloride (100230 propylene to Pmquce methylpentehes; These Prior art mesh). This catalyst was charged into a 300 cc. rocker catalysts may be in the form 0t liquid metal, as a film bomb along with 50 of dry heptane and 60 cc of on an men ,Support or as a sohd metal catalyst; liquid propylene. The reaction mass was heated at 200 Although It f Suggested any alkah meta] C. for 9 hours under a pressure of 825 p.s.i. No pressure suftable for dlmenzmg propylenexlt has found drop was observed during the reaction period and upon that m the apscnce of a Sewn? reactlye maienal an removal of the contents from the bomb and analysis therei alkali metals are equwalen} their ablhty to of, no hexenes were found, thus indicating no dimeriza- Pr9py1ene For p 1t 15 Wen k w h tion occurred and that elemental sodium on sodium chlopotassmm elther alone or on an men support W111 i h ride is an inactive catalyst with respect to its dimerization propylene to form methylpentenes. The predominatlng bility for propylene. isomer which is formed is 4-methylpentene-l. On the other hand, sodium, either alone or on an inert support, 40 Example U will not dimefile P py to form any methylpehtehes- The catalyst in this example was prepared by dispersing The l3resent invention is directed to a method of dimer sodium in Decalin, diluting with heptane, chilling the ilhlg Propylene under Conditions h that methyl mixture to 10 C. and adding a stoichiomctric amount Penttihes are the l f Product of the Teachoh and Sodium of n-amyl chloride. The resulting dispersion contained is the P y Catalyhc Component n-amyl sodium in approximately 0.75 molar amount. According to the invention, Propylehe is dimerized by 0 75 ml. of the dispersion were added to a 300 ml. rocking Contacting it with a Catalyst System Prepared by reacting autoclave and about 40 g. of propylene were introduced Sodium h an alkyl Chloride Containing Carbon therein. The mixture was heated to 150 C. and agitated at Pffifefflhly the two reactants are used in PP at that temperature for 2.5 hours. The bomb was then mately stoichiometric amounts. The resulting catalyst is r0 Cooled and unreacted propylene was vantei The a miX lre f 21 Sodium alkyl and Sodium Chloride which a maining material Was admixed with ml. of methanol components appear to form some sort of Complex y to destroy the catalyst and the hydrocarbon product was alkyl Chloride having from two to ten Carbon atoms can water Washed. The resulting product was distilled and be used in f rming the catalyst EXQHIPIES are ethyl the distillate boiling in the range of 50-90 C. was anachloride, n-propyl chloride, isobutyl chloride, n-amyl lyzed by vapor phase chromatography. The foregoing chloride, hexyl chloride, octyl chloride and decyl chloride. procedure was repeated twice except that reaction times On the other hand, the bromine and iodine analogues of of 4.5 and 6.5 hours were used. Results were as follows:

Product distribution, percent Reaction Percent time, hrs. conversion 4-MP*-1 4-MP-2 2-MP-1 2-MP-2 MPzmethylpentene.

These results show that the conversion of propylene to methylpentenes increases as the reaction time is increased but that the concentration of 4-methylpentene-l in the reaction product concurrently decreases.

I claim:

1. Method of dimerizing propylene to form a major amount of a mixture of 4-methylpentene-1 and 4-methylpentene-2 which comprises contacting propylene at a temperature in the range of 100 to 250 C. with a catalyst consisting essentially of the complex prepared by reacting sodium with an alkyl chloride containing 2 to 10 carbon atoms.

2. Method according to claim 1 wherein the temperature is in the range of 150 to 200 C.

3. Method of dimerizing propylene to form a major amount of a mixture of 4-methylpentene-1 and 4-methylpentene-Z which comprises contacting propylene at a temperature in the range of 100 to 250 C. with a catalyst 4 consisting essentially of the complex prepared by reacting sodium with normal amyl chloride.

4. Method according to claim 3 wherein the temperature is in the range of 150 to 200 C.

References Cited by the Examiner UNITED STATES PATENTS 2,548,803 4/1951 Little 260671 X 2,751,426 6/1956 Closson et al 260683.15 2,804,489 8/1957 Pines et al 260683.2 2,834,818 5/1958 Schmerling et al. 252476 X 2,994,725 3/1961 Shaw et al 260-671 X 3,075,027 1/1963 Bittner et al. 260683.15

ALPI-IONSO D. SULLIVAN, Primary Examiner.

PAUL M. COUGHLAN, Examiner. 

1. METHOD OF DIMERIZING PROPYLENE TO FORM A MAJOR AMOUNT OF A MIXTURE OF 4-METHYLPENTENE-1 AND 4-METHYLPENTENE-2 WHICH COMPRISES CONTACTING PROPYLENE AT A TEMPERATURE IN THE RANGE OF 100 TO 250*C. WITH A CATALYST CONSISTING ESSENTIALLY OF THE COMPLEX PREPARED BY REACTING SODIUM WITH AN ALKYL CHLORIDE CONTAINING 2 TO 10 CARBON ATOMS. 